I think the reason science criticism is difficult and rare is that while the scientific establishment is a mess and desperately needs reform it is constantly under siege by parts of the religious establishment.
Is this even true? The most obvious example of "Intelligent Design" is basically a brief footnote to Theory of Evolution stating that "God had something to do with it", to make it disagree less with other parts of people's belief network. It doesn't seem that much worse than similar footnote to the Big Bang Theory nearly every non-atheist holds. It's silly, but irrelevant.
I don't see any siege here.
I suppose Intelligent Design proponents try to portray it as a brief and uncontroversial footnote. But rather transparently it is the next in a long line of attempts to undermine or remove evolution from state biology curricula. This looks like a fight to me. I don't know what the history would look like if those fighting on behalf of science had been more critical of it but I think the scientific establishment's status as a credible arbiter of truth is pretty central to the argument that other 'ways of knowing' don't belong in science classes.
...It's sill
Please have a look at this Youtube user account. I immediately thought of this site upon watching a couple of his clips. I am told we have tried here to publish some stuff in audiovisual fomat, but it didn't quite work out. Maybe we should contact this guy, perhaps we could profit from each other's work and experience? I am fairly hopeful that he could use some of the material here, and we could use some of his talent with the medium.
This video, for instance, looks like it was taken right out of this very blog